Update Layer Hoisting to store its atlas texture in the resource cache

src/gpu/GrLayerHoister.h

 /*
  * Copyright 2014 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef GrLayerHoister_DEFINED
 #define GrLayerHoister_DEFINED
 
@@ skipping 15 matching lines @@
     SkMatrix         fLocalMat;
 };
 
 // This class collects the layer hoisting functionality in one place.
 // For each picture rendering:
 //  FindLayersToHoist should be called once to collect the required layers
 //  DrawLayers should be called once to render them
 //  UnlockLayers should be called once to allow the texture resources to be recycled
 class GrLayerHoister {
 public:
+    /** Attempt to reattach layers that may have been atlased in the past
+     */
+    static void Begin(GrContext* context);
+
+    /** Release cache resources
+     */
+    static void End(GrContext* context);
 
     /** Find the layers in 'topLevelPicture' that can be atlased. Note that the discovered
         layers can be inside nested sub-pictures.
         @param context    Owner of the layer cache (the source of new layers)
         @param topLevelPicture The top-level picture that is about to be rendered
         @param initialMat  The CTM of the canvas into which the layers will be drawn
         @param query       The rectangle that is about to be drawn.
         @param atlasedNeedRendering Out parameter storing the layers that 
                                     should be hoisted to the atlas
         @param recycled    Out parameter storing layers that are atlased but do not need rendering
@@ skipping 62 matching lines @@
     /** Update the GrTexture in 'layer' with its filtered version
         @param context    Owner of the layer cache (and thus the layers)
         @param device     Required by the filtering code
         @param info       Layer info for a layer needing filtering prior to being composited
      */
     static void FilterLayer(GrContext* context, SkGpuDevice* device, const GrHoistedLayer& info);
 
 };
 
 #endif